Kaoru Kaidō
Background Kaidō is mostly known for his "Snake Shot" (derived from the "Buggy Whip Shot"), a curving forehand that keeps his opponents running. He later develops the "Boomerang Snake," which is a shot that swerves out of bounds, around the net pole, and back in bounds. He developed the shot under mentor Sadaharu Inui's advice and by working with him in doubles. He usually plays the Singles 3 position, though he is most often placed in one of the Doubles slots. In Genius 379, the last chapter of the manga, Kaidō is seen as a third year and the new captain of Seigaku, with Momoshiro as his vice-captain. Their rivalry has, apparently, somewhat mellowed with time. Play style and Techniques Kaidō is a counterpuncher, noted by his stamina and retrieving most of the opponent's shot, using his physique to tire out his opponent first. While his play style becomes more aggressive as the series progresses, his original style is still evident in his matches. ;Snake Shot :A forehand or backhand shot that has an offset topspin that causes it to curve to the corners of the court, making the opponent run around and lose stamina. This is done by Kaidō shifting his weight from his right leg to his left and swings his racquet upwards while putting a lot of topspin on the ball with centrifugal force, making it go over the net in a crescent moon shaped fashion. The nature of this technique, however, makes this useless against Fuji's Tsubame Gaeshi, as noted by Kaidō himself. :In the anime, Snake is mostly depicted by a forehand, but in the manga, Kaidō uses a backhand Snake in his matches against Fudomine, Hyōtei, and Rokkaku. The only times a backhand Snake is shown in the anime is once in the Fudomine match, in stand-still shots in the matches against Hyōtei and Rikkai at the Regionals, and against Shitenhōji in the Nationals. :This is also called a Buggy Whip Shot, and is said to be used often by pros (i.e. Pete Sampras is mentioned to have used it). The Fudomine players refer to it as a Buggy Whip Shot in the manga as does Sadaharu Inui. In the anime, while Ryoma Echizen is playing Kaidō in the ranking matches, the turning point of the game is when Echizen realizes, and actually states, that the "Snake" is the Buggy Whip Shot. Sometime later, freshman Horio was also commenting on the excellence of Buggy Whip Shot, presumably when performed by Ryoma, much to the irritation of Kaidō. ;Boomerang Snake :Similar to the original Snake, the Boomerang Snake is a move from in which the tennis ball swings around the net in a sideways arch out of the court and back into the court on the other side instead of going over the net. It was initially performed by accident when he slipped while diving for the ball against Fudomine's Akira Kamio. Kaidō kept trying to use it after that, but the ball continually went into the alley, which in singles is out. It was still effective when playing doubles, where the alleys are counted as in, and it shocked all who were both in the game and watching it. The ref was even startled as it flew just below his chair. After that, Kaidō needed to spend a lot of time training in order to hit it properly during a singles match for it to count. Kaidō finally perfected the shot at the Kantō conference playing doubles with Inui against Hyōtei's Chōtarō Ootori and Ryō Shishidō. ;Short Snake :A variation of the Snake shot which has a much greater curve than the original. Instead of going deep into the corners, the Short Snake uses the curve to get around the net player. Kaidō first uses this move in his doubles match with Momoshiro against Bunta Marui and Kuwahara Jackal of Rikkai Daigaku Fuzoku to break Marui's net play. ;Reverse Snake :A Snake Shot that goes in the opposite direction of a normal Snake Shot. Kaidō develops this shot in order to prevent Jackal Kuwahaara from guessing where his shots were going and running to the corners before he even hit the shot. ;Tornado Snake :Yet another variation of the Snake, the Tornado Snake has a gyro spin version. Kaidō hits the ball with an upward facing backspin of a Magnus power and travel direction against a spin axis with a 45 degree entry angle. Because it's spinning, the ball barely receives any air resistance. Due to the spin, it's about 0.03 seconds faster than any other straight ball, as all noted by Konjiki Koharu of Shitenhōji. Kaidō first uses this technique at Nationals in the doubles match against Hyōtei, which he and Inui defeat Wakashi Hioyshi and Gakuto Mukahi. There are also different variations of the Tornado Snake. ;Gyro Laser :Formerly known as the "Laser Beam", this is an extremely fast forehand shot developed by Hiroshi Yagyū of Rikkai Daigaku Fuzoku. When Kaidō and Yagyū play an unofficial doubles match against a pair from Murigaoka, they disguise themselves as each other and each hit each others signature shots. Afterwards he asks Inui to help him hit the Laser Beam using the same form as the Tornado Snake. This technique makes its true debut against the Yanagi/Kirihara Pair. He adds in the same gyro spin as he would to the Snake Shot that makes his Laser Beam faster than Yagyū's. It was said by Inui that if Kaidō could hit Laser Beam using the same form as Tornado Snake it could confuse his opponent on which would come and that he might become invincible. ;Jack Knife :The Jack Knife, which is one of the signature shots of Kaidō's rival, Takeshi Momoshiro, is a very high level backhand shot in which the person hitting it jumps off the ground with their left foot. It is not only powerful, but fast as well, and it was stated a normal Junior High School student wouldn't be able to keep up with it. :While disguised, Kaidō and Momoshiro play against Hitōji and Konjiki of Shitenhōji. Kaidō hits the Jack Knife in order to cause the opponents to think he and Momoshiro had switched places. ;Devil Mode :This technique is similar to Kirihara's expanded Bloodshot Mode. Kaidō activates this state when Kirihara continuous hits the ball causing more injuries to his respective senior, Inui, during the national final D2 match. However, Inui is able to snap him out of this state. ;Hadoukyu Boomerang (Anime only) :This is a combination of the Hadoukyu technique and Boomerang Snake. The shot moves like Boomerang Snake shot, but it is very powerful and can knock the opponents racket out of their hand. Although the one-handed Hadoukyu is considered to be dangerous due to straining the arm, Kaidō is seen to have no problem using the one-handed shot for his Boomerang. Personality Kaidō's nickname "Mamushi", or the "Viper," which fits him well. He wears a bandana while playing tennis (in the anime, it is orange until episode 12 when it changes to green almost permentanly (only in a few, recreational episodes does it change color) and often exhales making a "fshuuuu" sound, similar to a snake. Kaidō does not like it when his nickname isn't taken seriously, and often reacts badly when called that within earshot by someone he doesn't like, especially if the person uttering the nickname is Takeshi Momoshiro or Akira Kamio (he once even comes to try hitting Kamio during the Fudomine matches, placing Tezuka in a rather uncomfortable situation). Despite his tough personality, Kaidō does have a soft spot for animals, as seen when he plays with Ryoma's cat Karupin in episode 27 and 73 and when he plays with a dog in episode 72. Kaidō trains rigorously, increasing the training program given to him by Inui to give him unbeatable endurance. Both he and Takeshi Momoshiro are second year regulars and rivals. They constantly try to one-up each other, which is actually beneficial for the growth of their tennis skills; this makes them extremely powerful as a doubles pair, because the two rivals know each other so well. Kaidō and Inui make an excellent doubles pair, mostly after beating Inui himself during the same line-up matches where Ryoma Echizen became a regular. Inui has seen Kaidō's potential and kind side and has taken him under his wing. In the fandom, they are often known as the "Emerald Pair." This is presumably a pun based on the name of Seigaku's "Golden Pair" (Eiji Kikumaru and Shūichirō Oishi) and the several green items associated with the Emerald Pair, such as Kaidō's bandana, Inui's notebook, Inui's special juices and pants he used when being the "training coach" of Seigaku after losing his regular place to Ryoma.